работает!!!

AutoService/Models/IProceedRepository.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AutoService.Models
+{
+    public interface IProceedRepository
+    {
+        public void SaveOrder(IEnumerable<Work> works, Order order);
+    }
+}

AutoService/Models/Order.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AutoService.Models
+{
+    public class Order
+    {
+        public string ClientName { get; set; }
+        public string AutoModel { get; set; }
+        public int ServiceId { get; set; }
+        public int TotalPrice { get; set; }
+        public int DiscountPercent { get; set; }
+    }
+}

AutoService/Models/ProceedRepository.cs

@@ -0,0 +1,76 @@
+using Microsoft.Extensions.Options;
+using MySqlConnector;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AutoService.Models
+{
+    public class ProceedRepository : BaseRepository, IProceedRepository
+    {
+        public ProceedRepository(IOptions<DatabaseSettings> databaseSettings) : base(databaseSettings)
+        {
+        }
+
+        public void SaveOrder(IEnumerable<Work> works, Order order)
+        {
+            try
+            {
+                OpenConnection();
+                string sql1 = "INSERT INTO orders (id, client_name, car_model, service_id, total_amount, discount_percent, order_date) VALUES(0, @ClientName, @AutoModel, @ServiceId, @TotalAmount, @DiscountPercent, @Date);";
+                string sql2 = "SELECT LAST_INSERT_ID() as id;";
+                string sql3 = "INSERT INTO auto_service_db.order_items (id, order_id, work_id, work_price) VALUES(0, @OrderId, @WorkId, @WorkPrice);";
+                using var transaction = connection.BeginTransaction();
+                int newId;
+                try
+                {
+                    using (var mc = new MySqlCommand(sql1, connection, transaction))
+                    {
+                        mc.Parameters.AddWithValue("@ClientName", order.ClientName);
+                        mc.Parameters.AddWithValue("@AutoModel", order.AutoModel);
+                        mc.Parameters.AddWithValue("@ServiceId", order.ServiceId);
+                        mc.Parameters.AddWithValue("@TotalAmount", order.TotalPrice);
+                        mc.Parameters.AddWithValue("@DiscountPercent", order.DiscountPercent);
+                        mc.Parameters.AddWithValue("@Date", DateTime.Now);
+                        mc.ExecuteNonQuery();
+                    }
+                    using (var mc = new MySqlCommand(sql2, connection, transaction))
+                    {
+                        var result = mc.ExecuteScalar();
+                        if (result != null)
+                        {
+                            newId = Convert.ToInt32(result);
+                        }
+                        else
+                        {
+                            throw new Exception("Это печально всё");
+                        }
+
+                    }
+                    foreach (var work in works)
+                    {
+                        using (var mc = new MySqlCommand(sql3, connection, transaction))
+                        {
+                            mc.Parameters.AddWithValue("@OrderId", newId);
+                            mc.Parameters.AddWithValue("@WorkId", work.Id);
+                            mc.Parameters.AddWithValue("@WorkPrice", work.Price);
+                            mc.ExecuteNonQuery();
+                        }
+                    }
+                    transaction.Commit();
+
+                }
+                catch (Exception ex)
+                {
+                    Console.WriteLine(ex);
+                }
+                CloseConnection();
+            }catch(Exception e)
+            {
+                Console.WriteLine(e);
+            }
+        }
+    }
+}

AutoService/Models/Work.cs

@@ -8,6 +8,7 @@ namespace AutoService.Models
 {
     public class Work
     {
+        public int Id { get; set; }
         public string Title { get; set; }
         public int Price { get; set; }
 

AutoService/Models/WorkRepository.cs

@@ -16,7 +16,7 @@ namespace AutoService.Models
 
         public IEnumerable<Work> GetByServiceId(int serviceId)
         {
-            string sql = "SELECT work_name, price FROM works WHERE service_id=@SID";
+            string sql = "SELECT id, work_name, price FROM works WHERE service_id=@SID";
             List<Work> result = new();
             try
             {
@@ -28,6 +28,7 @@ namespace AutoService.Models
                 {
                     result.Add(new Work()
                     {
+                        Id = reader.GetInt32("id"),
                         Title = reader.GetString("work_name"),
                         Price = reader.GetInt32("price")
 

AutoService/Program.cs

@@ -33,6 +33,7 @@ namespace AutoService
                 s.AddTransient<ReceiptWindow>();
                 s.AddSingleton<IWorkRepository,WorkRepository>();
                 s.AddSingleton<IServiceRepository, ServiceRepository>();
+                s.AddSingleton<IProceedRepository, ProceedRepository>();
                 s.AddSingleton<LocalContainer>();
                 
                 

AutoService/ViewModels/MainWindowVM.cs

@@ -1,4 +1,5 @@
 using AutoService.Models;
+using Avalonia.Controls.ApplicationLifetimes;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using Microsoft.Extensions.DependencyInjection;
@@ -38,6 +39,7 @@ namespace AutoService.ViewModels
             _container = localContainer;
             ClientName = "";
             AutoModel = "";
+  
             try
             {
                 services = new ObservableCollection<Service>(_serviceRepository.GetAll());
@@ -54,6 +56,7 @@ namespace AutoService.ViewModels
         [RelayCommand]
         public async Task StartWorksWindowAsync()
         {
+            var _currentWindow = (App.Current.ApplicationLifetime as IClassicDesktopStyleApplicationLifetime).MainWindow;
             if (ClientName.Length > 2 && AutoModel.Length > 2)
             {
                 if (!_container.StringValues.ContainsKey("ClientName"))
@@ -72,11 +75,13 @@ namespace AutoService.ViewModels
                 {
                     _container.StringValues["AutoModel"] = AutoModel;
                 }
-              
+                _container.SelectedService = SelectedService;
                 var vm = _serviceProvider.GetRequiredService<WorksWindowVM>();
                 var win = _serviceProvider.GetRequiredService<WorksWindow>();
                 win.DataContext = vm;
+                vm.SetWindow(win);
                 win.Show();
+                _currentWindow.Close();
             }
             else
             {

AutoService/ViewModels/ReceiptWindowVM.cs

@@ -1,6 +1,8 @@
 using AutoService.Models;
+using Avalonia.Controls;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
+using Microsoft.Extensions.DependencyInjection;
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
@@ -17,6 +19,9 @@ namespace AutoService.ViewModels
         
         private readonly LocalContainer _localContainer;
 
+        private readonly IProceedRepository _proceedRepository;
+
+        public Button Btn { get; set; }
 
         [ObservableProperty]
         private ObservableCollection<Work> works;
@@ -31,10 +36,16 @@ namespace AutoService.ViewModels
 
         [ObservableProperty]
         private double totalPrice;
-        public ReceiptWindowVM(IServiceProvider serviceProvider, ObservableCollection<Work> works, LocalContainer localContainer)
+        private ReceiptWindow _currentWindow;
+        
+        
+
+
+        public ReceiptWindowVM(IServiceProvider serviceProvider, ObservableCollection<Work> works, LocalContainer localContainer, ProceedRepository proceedRepository)
         {
             _serviceProvider = serviceProvider;
             _localContainer = localContainer;
+            _proceedRepository = proceedRepository;
             Works = works;
             foreach (var item in Works) sumPrice += item.Price;
             if (sumPrice >= 10_000) discount = 0.1;
@@ -47,7 +58,33 @@ namespace AutoService.ViewModels
         [RelayCommand]
         public void ProceedTransaction()
         {
+            Order order = new Order
+            {
+                ClientName = _localContainer.StringValues["ClientName"],
+                AutoModel = _localContainer.StringValues["AutoModel"],
+                DiscountPercent=(int)(discount*100),
+                ServiceId=_localContainer.SelectedService.Id,
+                TotalPrice=(int)TotalPrice
+            };
+            _proceedRepository.SaveOrder(Works, order);
+            Btn.IsEnabled = false;
 
         }
+        [RelayCommand]
+        public void ReturnToMain()
+        {
+            var vm = _serviceProvider.GetRequiredService<MainWindowVM>();
+            var win = _serviceProvider.GetRequiredService<MainWindow>();
+            win.DataContext = vm;
+            win.Show();
+            _currentWindow.Close();
+
+        }
+
+
+        public void SetWindow(ReceiptWindow window)
+        {
+            _currentWindow = window;
+        }
     }
 }

AutoService/ViewModels/WorksWindowVM.cs

@@ -20,7 +20,7 @@ namespace AutoService.ViewModels
 
         [ObservableProperty]
         private ObservableCollection<WorkIsChecked> works;
-
+        private WorksWindow _currentWindow;
 
         public WorksWindowVM(IServiceProvider serviceProvider, IWorkRepository workRepository, LocalContainer container)
         {
@@ -47,10 +47,18 @@ namespace AutoService.ViewModels
             {
                 if (work.IsChecked) selectedWorks.Add(work.Work);
             }
-            var vm = ActivatorUtilities.CreateInstance<ReceiptWindowVM>(_serviceProvider, selectedWorks, _localContainer);
+            var procRep = _serviceProvider.GetRequiredService<IProceedRepository>();
+            var vm = ActivatorUtilities.CreateInstance<ReceiptWindowVM>(_serviceProvider, selectedWorks, _localContainer, procRep);
             var win = _serviceProvider.GetRequiredService<ReceiptWindow>();
             win.DataContext = vm;
+            vm.SetWindow(win);
+            vm.Btn = win.ProceedBtn;
             win.Show();
+            _currentWindow.Close();
+        }
+        public void SetWindow(WorksWindow window)
+        {
+            _currentWindow = window;
         }
 
     }

AutoService/Views/ReceiptWindow.axaml

@@ -28,6 +28,8 @@
 			<TextBlock Text="Итого к оплате: "/>
 			<TextBlock Text="{Binding TotalPrice}"/>
         </StackPanel>
-        <Button Content="Подтвердить!" Command="{Binding ProceedTransactionCommand}"/>
+        <Button Content="Подтвердить!" Command="{Binding ProceedTransactionCommand}" x:Name="ProceedBtn"/>
+        <Button Content="Вернуться в окно выбора услуг" Command="{Binding ReturnToMainCommand}"/>
+
     </StackPanel>
 </Window>